US Fires National Security Twitter Critic

The White House has fired a national security adviser who anonymously posted hundreds of comments on Twitter that were highly critical of U.S. foreign affairs policies and key aides to President Barack Obama.

The official, 40-year-old Jofi Joseph, was dismissed last week after investigators spent months trying to identify the person making the comments under the pseudonym @natsecwonk (national security wonk). He was the nuclear non-proliferation director at the National Security Council and had been involved in recent negotiations on Iran's nuclear weapons program.

In a statement to the Politico news site, Joseph took responsibility for the tweets he made over the last two years and apologized "to everyone I insulted." Joseph said he originally intended his comments as a parody of life in highly politicized Washington, but they evolved into "a series of inappropriate and mean-spirited comments."

Joseph spared few officials in U.S. national security circles, criticizing Secretary of State John Kerry and his predecessor, Hillary Clinton, as well as White House adviser Ben Rhodes. He questioned the official account of how four U.S. diplomats were killed in Benghazi, Libya in 2012. Joseph also attacked U.S. Republican officials, including Sarah Palin, the party's 2008 vice presidential candidate.